Rotary electric switch



Oct. 24, 1961 o. T. ELLSWORTH ROTARY ELECTRIC SWITCH Filed Nov. 28, 1960 FIG. 5.

IN VEN TOR. ORVAL T. ELLSWORTH BY ATTORNEY Unitcd StateSIPatent O F 3,005,881 r ROTARY ELECTRIC SWITCH Orval T. Ellsworth, Long Beach, Cahf. (11742 Braddock Drive, Culver City, Calif.)

. Filed Nov. 28, 1960, Ser. No. 71,980

8 Claims. (Cl. 200-11) This invention relates to a rotary electric switch which has many uses in different fields;'however, it is particularly useful in connection with an electroencephelograph, or similar structures such as computers and the like.

The conventional rotary switch has an. internal rotary selector with co-acting external contacts, whereas my rotary switch has the rotary selector on the outside and surrounding a circular array of input contacts, and these input contacts are preferably in the form of elongated 'bus bars. The bus bars are positioned on the periphery of an elongated shaft. With this construction I greatly simplify the wiring arrangement over equivalent circuitry with a conventional switch.

Another object of my invention is to provide a novel rotary electric switch which providesan inline display of selector positions for easy observation by the operator.

Still another object of my invention is to provide a novel rotary electric switch in which a plurality of rotatably mounted selectors maybe positioned immediately adjacent to each other, and each of these selectors are mounted on the same shaft which carries the external bus bars on the shaft and through which electrical current is fed to each of the rotary selectors.

Still another object is to provide a novel rotary switch in which the various current carrying bus bars are on the outside of a shaft and thus are more easily available for repair or replacement as might be required.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

In the drawing:

FIGURE 1 is a side elevation of my rotary electric switch.

FIGURE 2 is a sectional view taken on line 2-2 of FIG. 1.

FIGURE 3 is an exploded perspective view of my electric switch.

FIGURE 4 is an enlarged sectional view taken on line 4-4 of FIG. 2.

FIGURE 5 is a sectional view taken on line 5-5 of FIG. 4.

Referring more particularly to the drawing, the numeral 1 indicates a shaft which is fixedly mounted between end plates 2 and 3. The shaft 1 is stationary and is fixed in the end plates 2 and 3. A plurality of circumferentially spaced contact wires or bus bars 4 are partially embedded in the periphery of the shaft 1, and these bus bars protrude slightly above the external surface of said shaft. The bus bars 4 extend substantially the entire length of the shaft 1 and they lead to the end plate 2, where suitable conduits 5 are formed or imprinted in this plate and extend from each bus bar 4 to a suitable terminal or plug 6. The contact 6 may be engaged by suitable electrical terminals 7 which extend to the particular circuitry in a device such as an electroencephelograph. At intervals throughout the length of the shaft 1 I provide a plurality of spaced rings 8 and these rings are held stationary in the following manner: Ks et screw 9 extends through the ring 8 and into a metal sleeve or terminal 10 embedded in the shaft 1. An input conductor 11 extends from the metal terminal 10 through the shaft 1, and thence to a suitable input lead 12 in the plate 2. Input current is thus fed through the lead 11,

3,005,881 Patented Oct. 24, 1961 ice thence tothe threaded sleeve 10, and finally to an annular contact 13 on one face of the stationary ring 8. The set screw 9 serves to not only hold the ring 8 stationary, but also insures a good contact between the metal sleeve 10 and the annular contact 13. A plurality of rotary selector rings 14 are provided one adjacent each of the contact rings 8. The selector rings 14 are toothed or grooved so that they can be readily engaged and manipulated by the fingers of the operator. A flange 15 is provided on each of the selector rings 14, and this flange is provided with an annular contact 16 which is positioned opposite the contact 13 and slidably engages this contact. Thus current is fed from the annular contact 13 to the contact 16, and thence to a finger 17 which extends inwardly from the contact 16 to selectively engage and contact any one of the bus bars 4. The circuit is thus completed from the input lead 11, thence to the annular contact 13 through the metal nut 10, thence to the contact ring 16 to the finger 17, and then to the bus bar 4 and finally to the output lead 5.

If it is desired to hold the selector rings 14 in their various contacting positions with the bus bars 4, I may provide a spring detent 18 in each of the selector rings, and the spring detents enter suitable indentations 19in the stationary rings 8, thus insuring that the proper contact will be held until the selector ring is again moved by the operator.

Having described my invention, I claim:

1. A rotary .electric switch comprising a stationary shaft, supporting means in which the shaft is mounted, a plurality of circumferentially spaced bus bar conduits on the outside surface of said shaft, a stationary ring mounted on the shaft, an annular contact on one vertical face of the stationary ring, conductor means extending to the annular contact, a selector ring journaled on the shaft, a contact finger on said selector ring engageable with any one of said bus bars, and contact means connected to the contact finger and engageable with said annular contact.

2. A rotary electric switch comprising a stationary shaft, supporting means in which the shaft is mounted, a plurality of circumferentially spaced bus bar conduits on the outside surface of said shaft, a stationary ring mounted on the shaft, an annular contact on one vertical face of the stationary ring, conductor means extending to the annular contact, a selector ring journaled on the shaft, a contact finger on said selector ring engageable with any one of said bus bars, and contact means connected to the contact finger and engageable with said annular contact, and an output lead extending from each of said bus bars.

3. A rotary electric switch comprising a stationary shaft, end plates supporting said stationary shaft, a plurality of circumferentially spaced bus bar conduits on the outside surface of said shaft, a stationary ring mounted on the shaft, an annular contact on one vertical face of the stationary ring, conductor means extending to said annular contact, a selector ring journaled on the shaft and positioned adjacent said stationary ring, a contact finger on said selector ring engageable with any one of said bus bars, and contact means connected to the con tact finger and engageable with said annular contact.

4. A rotary electric switch comprising a stationary shaft, end plates supporting said stationary shaft, a plurality of circumferentially spaced bus bar conduits on the outside surface of said shaft, a stationary ring mounted on the shaft, an annular contact on one vertical face of the stationary ring, conductor means extending to said annular contact, a selector ring journaled on the shaft and positioned adjacent said stationary ring, a contact finger on said selector ring engageable with any one of said bus bars, and contact means connected to the contact finger and engageable with said annular contact, and an output lead extending from each of said busbars, said output leads being arranged in one of said end plates.

5. A rotary electric switch comprising a stationary shaft, end plates supporting said stationary shaft, a plurality of circumferentially spaced bus bar conduits on the outside surface of said shaft, a stationary ring mounted on the shaft, an annular contact on one vertical face of the stationary ring, conductor means extendnig tosaid annular contact, a selector ring journaled on the shaft and positioned adjacent said stationary ring, a contact finger on said selector ring engageable with any one of said bus bars, and an annular contact on one face of said selector ring positioned opposite and engageable with said first named annular contact, said contact finger being connected to the last named annular contact.

6. A rotary electric switch comprising a stationary shaft, end plates supporting said stationary shaft, a plurality of 'circumferentially spaced bus bar conduits on the outside surface of said shaft, a stationary ring mounted on the shaft, an annular contact on one vertical face of the stationary ring, conductor means extending to said annular contact, a selector ring journaled on the shaft and positioned adjacent said stationary ring, a contact finger on said selector ring engageable with any one of said bus bars, and an annular contact on one face of said selector ring positioned opposite and engageable with said first named annular contact, said contact finger being connected to the last named annular contact, and

an output lead extending from each of said bus bars, said output leads being positioned in one of said end plates.

7. A rotary electric switch comprising a stationary shaft, an end plate in which the shaft is fixedly mounted,

a plurality of circumferentially spaced bus bar conduits on the outside surface of said shaft, a stationary ring mounted on the shaft, an annular contact on one vertical face of the stationary ring, an electrical conductor extending through the shaft and to said annular contact, a selector ring journaled on the shaft and positioned adjacent the stationary ring, a contact finger on said selector ring engageable with any one of said bus bars, an annular contact on the selector ring positioned opposite to and engageable with the first named annular contact on the stationary ring.

8. A rotary electric switch comprising a stationary shaft, an end plate in which the shaft is fixedly mounted, a plurality of circumferentially spaced bus bar conduits on the outside surface of said shaft, a stationary ring mounted on the shaft, an annular contact on one vertical face of the stationary ring, an electrical conductor extending through the shaft and to said annular contact, a selector ring journaled on the shaft and positioned adjacent the stationary ring, a contact finger on said selector ring engageable with any one of said bus bars, an annular contact on the selector ring positioned opposite to and engageable with the first named annular contact on the stationary ring, and an output lead extending from each of said bus bars, said output leads being arranged in one of said end plates.

References Cited in the file of this patent UNITED STATES PATENTS 2,201,882 Bryant et a1. May 21, 1940 FOREIGN PATENTS 760,989 France Dec. 27, 1933 

